A tandem type image forming apparatus that employs the intermediate transfer method is provided with: a processing unit such as a process unit including a photoreceptor drum, a developing unit including a developer bearing member, and an exposure unit including an exposure member; and an intermediate transfer unit. In a case in which these units are incorporated in the apparatus body of the image forming apparatus separately, in order not to damage the photoreceptor drum when the units are inserted into the apparatus body, it is necessary to provide a space between the developing unit or the intermediate transfer unit and the photoreceptor drum. Therefore, the accuracy of relative positions between the units is reduced and a color shift occurs, which causes a risk that an image quality may be reduced.
In view of the foregoing, an image forming apparatus having a configuration in which a plurality of processing units are linked and integrated by being mounted on a tray and a configuration in which each of the plurality of processing units is provided with a link portion in order to link the plurality of process units to each other has been known (see Patent Literature 1, for example). In such a conventional image forming apparatus, both positioning and link fixing of the plurality of processing units are performed by a single means such as a tray or a link portion.